Context: Hospital-to-home transitions, particularly at the end of life, can be challenging for patients and their family caregivers. Therefore, there is a need to better understand gaps in expectations and experiences of these transitions. Theory can inform the creation of an intervention aimed at improving the hospital-to-home transition. Objectives: 1) Explore patients' and caregivers' expectations and subsequent experiences of the hospital-to-home transition while receiving palliative care, and 2) build a substantive grounded theory to enhance the understanding of hospital-to-home transitions from the patient and caregiver perspective. Methods: Longitudinal, prospective qualitative study with semistructured interviews at hospital discharge and three to four weeks after discharge home. We recruited adults receiving inpatient palliative care who were being discharged to home-based palliative care, and their family caregivers from two academic health centers in Toronto, Canada. Thirty-nine participants: 18 patients, 7 caregivers, and 7 patient-caregiver dyads participated. We conducted 52 interviews. We conducted a grounded theory qualitative study. Results: Through examining the expectations and subsequent experiences of the transition, and exploring the gaps between them, we identified various transitions needs: health and well-being needs, and practical needs (i.e., transportation, setting up the home for care, care providers in the home). Several enablers and disablers modified the likelihood of needs being met (e.g., caregiver role, education on symptom management, uncertainty, financial resources). Conclusion: Our substantive grounded theory highlighted potentially measurable constructs that can be further tested. Future interventions should target the enablers/disablers to ensure health and well-being and practical needs are met in the transition.